In the related art, in order to adjust a posture, there is a vehicle seat apparatus capable of adjusting a position of configuring elements of a vehicle seat, such as a seat cushion or a seat back, using a drive source. For example, JP 2001-277909A discloses a seat slide apparatus capable of adjusting a slide position of the seat cushion using a motor drive. That is, the seat slide apparatus includes a lower rail fixed to a vehicle floor and an upper rail provided to be relatively movable with respect to the lower rail. Then, a configuration is adopted in which the upper rail is moved along the extending direction of the lower rail, based on the drive force of a motor.
Furthermore, the seat slide apparatus detects a movement position of the upper rail by counting (integrating) motor pulses, that is, pulse edges of output pulse signals using a rotation sensor provided in the motor. Then, a function, for example, such as a so-called memory seat which returns the seat to a memorized position by performing a position control accordingly can be installed.
In addition, it is necessary to identify a rotation direction of the motor in order to accurately detect position by counting such motor pulses. However, after the motor drive is stopped, it is no longer possible to identify the rotation direction from a control command thereof. In this regard, in the above-described related art, after the motor drive is stopped, the influence due to deflection occurring in a power transmission member thereof is considered and the count rate of the motor pulses is corrected. Then, accordingly, a configuration to reduce an error in detecting the position is adopted.
However, in a stage before movement of a seat is regulated by a slide lock mechanism, factors other than deflection of a power transmission member as described above, for example, when parking on a hill or the like may cause the position of the seat to be moved. In this case, there is still a possibility that a detection error may occur since the rotation direction of a motor cannot be identified. Then, such a detection error may occur in other vehicle seat apparatuses such as a seat reclining apparatus, a seat lifting apparatus or an ottoman apparatus, for example, and there has also been a need for improvements thereof.
A need thus exists for a vehicle seat apparatus which is not susceptible to the drawback mentioned above. A need thus exists for a vehicle seat apparatus capable of identifying a rotation direction after a motor drive is stopped, with a simple configuration, and capable of suppressing the occurrence of an error in detecting a position based on counting motor pulses thereof.